A control apparatus for a vehicle for controlling the operation of each portion of the vehicle such as an automobile, etc. uses a computer such as a microcomputer, etc. In such a control apparatus for a vehicle, various kinds of controls are realized by executing a control program stored in a memory device such as a ROM, etc. by the computer.
The control program for a vehicle is generally constructed by dividing this control program into a platform program (PF) as a program depending on hardware, and an application program (AP) as a program depending on the control for the vehicle.
The platform program is for making the computer execute processing for inputting data from a hardware device and providing data based on these inputted data with respect to processing using the application program through an interface (PF interface) such as API (Application Program Interface), and outputting data acquired through this PF interface from the processing using the application program to the hardware device.
On the other hand, the application program is for making the computer execute processing using data inputted through this PF interface, and processing for generating data outputted through the PF interface. For example, the application program makes the computer execute processing for generating the data outputted through the PF interface on the basis of the data inputted through the PF interface.
Thus, the platform program includes a program for getting access to the hardware device. In contrast to this, the application program does not include a program for directly getting access to the hardware device. In the application program, input and output operations with respect to the hardware device are performed in the processing using the platform program through the PF interface. Thus, a developer of the application program can make the application program without being conscious of the detailed construction and the control method of hardware.
Further, for example, as disclosed in JP-A-07-040794, a control unit for an automobile has interface software for connecting an operating system and application software. An arithmetic calculation of signals required in the application software is made by the interface software. Thus, even when the hardware is changed, the “application software” can be permanently used only by rewriting the interface software.
However, in a maker of the control apparatus for a vehicle, there are many cases in which the development of plural control apparatus for vehicles having different required specifications is requested from a vehicle maker as a customer. It is necessary to newly make the application program in accordance with each of the required specifications. Accordingly, a technique for reducing development cost by diverting the platform program as much as possible and constructing the control program for a vehicle is adopted instead of the technique of diverting the “application program software” and making the control program for a vehicle.
To divert the platform program, for example, a common item is extracted between the different required specifications, and the platform program is constructed so as to provide the PF interface standardized by this common item. For example, the PF interface specification as the specification of the PF interface is standardized so as to provide data to the processing using the application program in a data format, data provision timing, etc. conformed to the most strict required specification among the respective required specifications.
For example, in an engine control apparatus, when processing based on a voltage value from a water temperature sensor for detecting the temperature of cooling water of the engine is performed, the required specification is V/256 as resolution of this voltage value in the engine control apparatus A of a certain vehicle kind. In contrast to this, the required specification is set to v/128 as resolution in the engine control apparatus B of another vehicle kind. In such a case, the PF interface specification for providing the PF interface for the processing using the application program is planned and determined by resolution V/256 conformed to the engine control apparatus A of fine resolution so as to satisfy the required specifications of the engine control apparatus of both the vehicle kinds in the processing using the platform program. The platform program is constructed so as to provide the PF interface along this PF interface specification. Thus, the same platform program can be diverted in the engine control apparatus having the different required specifications.
However, when the application program of the engine control apparatus B is made, the resolution of the required specification is V/128. In contrast to this, the resolution provided by the PF interface using the platform program is V/256. Therefore, it is necessary for a developer of the application program to build into the application program a resolution conversion processing program for compensating for the gap between the resolution of the PF interface specification using the platform program and the resolution of the required specification of the control apparatus for a vehicle of a developing object.
As such a required specification, there are various elements such as the kind of data, the type of data, fetch timing of data, etc. in addition to the resolution. When the application program utilizing the standardized platform program in the control apparatus for vehicles having the different required specifications is made, it is necessary for the developer of the application program to consider a method for realizing the required specification by always thinking of the PF interface specification provided by the platform program. Therefore, the burden of the developer of the application program is large.